Excited-state dynamics of donor-acceptor bridged systems containing a boron-dipyrromethene chromophore: Interplay between charge separation and reorientational motion

被引:77
作者
Duvanel, Guillaume [1 ]
Banerji, Natalie [1 ]
Vauthey, Eric [1 ]
机构
[1] Univ Geneva, Dept Phys Chem, CH-1211 Geneva, Switzerland
关键词
D O I
10.1021/jp071560o
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
The excited-state dynamics of a series of electron donor-acceptor bridged systems (DABS) consisting of a boron-dipyrromethene chromophore covalently linked to a dinitro-substituted triptycene has been investigated using femtosecond time-resolved spectroscopy. The chromophores differ by the number of bromine atom substituents. The fluorescence lifetime of the DABS without any bromine atom is strongly reduced when going from toluene to polar solvents, this shortening being already present in chloroform. This effect is about 10 times weaker with a single bromine atom and negligible with two bromine atoms on the chromophore. The excited-state lifetime shortening is ascribed to a charge transfer from the excited chromophore to a nitrobenzene moiety, the driving force of this process depending on the number of bromine substituents. The occurrence of this process is further confirmed by the investigation of the excited-state dynamics of the chromophore alone in pure nitrobenzene. Surprisingly, no correlation between the charge separation time constant and the dielectric properties of the solvents could be observed. However, a good correlation between the charge separation time constant and the diffusional reorientation time of the chromophore alone, measured by fluorescence anisotropy, was found. Quantum chemistry calculations suggest that quasi-free rotation about the single bond linking the chromophore to the triptycene moiety permits a sufficient coupling of the donor and the acceptor to ensure efficient charge separation. The charge separation dynamics in these molecules is thus controlled by the reorientational motion of the donor relative to the acceptor.
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页码:5361 / 5369
页数:9
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共 84 条
[41]   A novel fluorescent probe for zinc ion based on boron dipyrromethene (BODIPY) chromophore [J].
Koutaka, H ;
Kosuge, J ;
Fukasaku, N ;
Hirano, T ;
Kikuchi, K ;
Urano, Y ;
Kojima, H ;
Nagano, T .
CHEMICAL & PHARMACEUTICAL BULLETIN, 2004, 52 (06) :700-703
[42]   Rigidified tetrathiafulvalene-[60]fullerene assemblies: towards the control of through-space orientation between both electroactive units [J].
Kreher, D ;
Cariou, M ;
Liu, SG ;
Levillain, E ;
Veciana, J ;
Rovira, C ;
Gorgues, A ;
Hudhomme, P .
JOURNAL OF MATERIALS CHEMISTRY, 2002, 12 (07) :2137-2159
[43]   ELECTRON-TRANSFER IN ORGANIC GLASS - DISTANCE AND ENERGY-DEPENDENCE [J].
KRONGAUZ, VV .
JOURNAL OF PHYSICAL CHEMISTRY, 1992, 96 (06) :2609-2613
[44]   POLARIZATION-DEPENDENT 2-PHOTON SPECTRA OF TRIPTYCENE [J].
KUNDU, T ;
NATH, D ;
SAMANTA, A ;
CHOWDHURY, M .
CHEMICAL PHYSICS LETTERS, 1987, 133 (06) :507-512
[45]   DEVELOPMENT OF THE COLLE-SALVETTI CORRELATION-ENERGY FORMULA INTO A FUNCTIONAL OF THE ELECTRON-DENSITY [J].
LEE, CT ;
YANG, WT ;
PARR, RG .
PHYSICAL REVIEW B, 1988, 37 (02) :785-789
[46]   Design, synthesis, and photodynamics of light-harvesting arrays comprised of a porphyrin and one, two, or eight boron-dipyrrin accessory pigments [J].
Li, FR ;
Yang, SI ;
Ciringh, YZ ;
Seth, J ;
Martin, CH ;
Singh, DL ;
Kim, DH ;
Birge, RR ;
Bocian, DF ;
Holten, D ;
Lindsey, JS .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1998, 120 (39) :10001-10017
[47]   Effects of gel material on fluorescence lifetime detection of dyes and dye-labeled DNA primers in capillary electrophoresis [J].
Li, LJ ;
McGown, LB .
JOURNAL OF CHROMATOGRAPHY A, 1999, 841 (01) :95-103
[48]   TIME-RESOLVED FLUORESCENCE STUDIES ON COVALENTLY-LINKED PORPHYRIN NITROARENE COMPLEXES - CONFORMATIONAL CONTROL OF PHOTOINDUCED ELECTRON-TRANSFER REACTIONS [J].
MAIYA, BG ;
DORAISWAMY, S ;
PERIASAMY, N ;
VENKATARAMAN, B ;
KRISHNAN, V .
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY, 1994, 81 (03) :139-150
[49]   ELECTRON TRANSFERS IN CHEMISTRY AND BIOLOGY [J].
MARCUS, RA ;
SUTIN, N .
BIOCHIMICA ET BIOPHYSICA ACTA, 1985, 811 (03) :265-322
[50]   INTRAMOLECULAR LONG-DISTANCE ELECTRON-TRANSFER IN RADICAL-ANIONS - THE EFFECTS OF FREE-ENERGY AND SOLVENT ON THE REACTION-RATES [J].
MILLER, JR ;
CALCATERRA, LT ;
CLOSS, GL .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1984, 106 (10) :3047-3049